Atomic force microscopy is used to investigate the possibility of crack tip cavitation during crack growth in silicate glasses. Matching areas on both surfaces of a crack were mapped and then compared for soda-lime silicate glass and for silica glass. For both glasses surfaces matched to better than 0.3 nm normal to the surface and 5 nm parallel to the surface. We could find no evidence for cavity formation in our study and suggest that completely brittle fracture occurs in glass.